Methods and apparatuses for joining a pumping cartridge to a pump drive

ABSTRACT

Apparatus and methods of their use are described for engaging a pumping cartridge with a pump drive. In certain embodiments, the cartridge, comprising a cylinder and a movable piston assembly, is initially assembled or subsequently positioned so that the distance between the attachment point on the piston assembly for coupling to a drive assembly, and a reference point on the cylinder, is greater than the maximal distance that will be encountered during normal oscillation of the piston during use. The cartridge, in certain embodiments may be pressed into a drive assembly having means for immobilizing the cartridge and means for coupling the piston assembly to the driveshaft. In certain embodiments, when the cartridge is fully inserted into the drive assembly, the piston is pressed into the cylinder sufficiently to establish a selected distance so that the piston shaft is in the proper position to engage with a coupling mechanism carried on the driveshaft.

RELATED APPLICATIONS

[0001] This non-provisional application claims the benefit under Title35, U.S.C. §119(e) of co-pending U.S. Provisional Application Ser. No.60/440,123, filed, Jan. 15, 2003, which is incorporated herein byreference. This application is a continuation-in-part of U.S.application Ser. No. --/---,---(not yet assigned), filed Jan. 9, 2004under Attorney Docket No. S1192.70030US01, titled: HIGH PRESSURE PUMPINGCARTRIDGES FOR MEDICAL AND SURGICAL PUMPING AND INFUSION APPLICATIONS,by: Timothy E. Moutafis and David M. Fischer, now pending; which is acontinuation of U.S. application Ser. No. 10/134,970, filed Apr. 29,2002, now abandoned; which claims priority to U.S. ProvisionalApplication Ser. No. 60/287,219, filed Apr. 27, 2001, each of which isincorporated herein by reference.

BACKGROUND

[0002] 1. Field of the Invention

[0003] The invention relates generally to pumping systems employingpumping cartridges that can be disengaged from a pump drive unit, and,more specifically to methods of joining a pumping cartridge to a pumpdrive in such pumping systems and interconnect mechanisms facilitatingsuch methods.

[0004] 2. Description of the Related Art

[0005] A piston pump typically includes several cooperating elements.These typically include at least a cylinder, a piston moving in thecylinder, and a drive shaft connected to the piston that moves thepiston back and forth in the cylinder. Other elements typically includeone or more check valves, or functional equivalents, so that fluid isdrawn in from a source and expelled into an outlet. Normally, the driveshaft is permanently fastened to a mechanism providing the reciprocalmotion.

[0006] In certain medical applications, it may be desirable to providedisposable pump elements that contact fluids being pumped, e.g.disposable piston pumping cartridges, for example to preventtransmission of disease between patients. For the sake of economy, itmay be advantageous for the mechanism providing reciprocating force tobe separate from the pumping elements. The disposable portion of apiston pump, typically comprising a cylinder, a piston, and valves, canadvantageously be fabricated as a separate cartridge. The cartridge can,for certain applications, be provided in a sterile condition, so thatthe fluid pumped will not be contaminated. Such a cartridge can beconfigured to be reversibly attached to a reusable drive mechanism,typically comprising a motor, which reciprocates the piston via, forexample, a reversible linkage.

[0007] In one mode of medical use, such as described in certain of theApplicant's commonly owned patents and patent applications (e.g. U.S.Pat. Nos. 6,216,573; 5,944,686; 6,375,635; 6,511,493; and U.S. Pat.Application Pub. No. 2002/0176788-A1, each incorporated herein byreference), such a disposable cartridge can used to generate a highpressure, such as 5,000 p.s.i, 10,000 p.s.i, or 20,000 p.s.i or more.The resulting high pressure water jet can be used, for example, to cutand/or remove and/or clean tissue, or to drive rotary tissue-abradingelements. In one mode of making such cartridges, described in moredetail in commonly-owned US 2002/0176788-A1, the piston is provided withan abradable flange as a sealing element. Such disposable cartridgesmay, in certain embodiments, be designed to be used only for a singlemedical procedure, and thus may require relatively frequent replacement.

[0008] In a medical environment, such as an operating room, there areseveral constraints that may be desirable to be satisfied in a procedurefor coupling a piston to a drive that make such a procedure technicallychallenging. First, it may be desirable that the connection can be madewithout removing the piston from the cylinder, since that would tend torender the pumping zone non-sterile. Second, may be desirable for it tobe possible for the operator to be able to replace the pump while theoperator is wearing gloves, and without contaminating the operator (whowill typically be a physician or a nurse.) Third, it may be desirablethat the connection method can enable the disposable components to becoupled to the resuable components reliably on the first try and withoutextensive operator training or difficulity. In addition, it may bedesirable that the connection mechanism be able to be fabricatedeconomically so as to add as little expense to the overall disposablecartridge as possible.

SUMMARY

[0009] Apparatuses and methods for connecting a disposable pumpingcartridge to a pump drive that can, in certain embodiments, meet one,more, or all of the above requirements are described. In an exemplaryembodiment, a method and system of coupling is described that comprises“parking” a piston in a portion of a cylinder that is other than itsnormal operating zone, and that is positioned farther from a highpressure fluid-containing end of the cartridge than the operating zone.This “Parking” procedure can be used to position a piston in a cylinderso than when the cartridge is inserted into a drive, the piston can,optionally without further intervention, be positioned so that aprovided coupling mechanism can, in some cases reliably and simply,couple the piston to the drive mechanism.

[0010] Apparatus and methods of their use are described for engaging apumping cartridge with a pump drive. In certain embodiments, thecartridge, comprising a cylinder and a movable piston assembly, isinitially assembled or subsequently positioned so that the distancebetween the attachment point on the piston assembly for coupling to adrive assembly, and a reference point on the cylinder, is greater thanthe maximal distance that will be encountered during normal oscillationof the piston during use. The cartridge, in certain embodiments may bepressed into a drive assembly having means for immobilizing thecartridge and means for coupling the piston assembly to the driveshaft.In certain embodiments, when the cartridge is fully inserted into thedrive assembly, the piston is pressed into the cylinder sufficiently toestablish a selected distance so that the piston shaft is in the properposition to engage with a coupling mechanism carried on the driveshaft.

[0011] In a first series of embodiments, a method for reversiblycoupling a pumping cartridge to a reusable pump drive system isdescribed. The method comprises: providing the reusable pump drivesystem with a first pumping cartridge retaining component configured andpositioned to enable it to engage a first portion of the cartridge, thefirst pumping cartridge retaining component being adjustable between aretaining position and a non-retaining position; providing a driveshaftof the reusable pump drive system with a second pumping cartridgeretaining component configured and positioned to enable it to engage asecond portion of the cartridge comprising a portion of a piston shaftof the pumping cartridge, the second pumping cartridge retainingcomponent being adjustable between a retaining position and anon-retaining position; preparing the pumping cartridge for connectionto the reusable pump drive system by placing a piston of the pumpingcartridge in a selected position relative to a cylinder of the pumpingcartridge; inserting the pumping cartridge into the reusable pump drivesystem; adjusting the first and second pumping cartridge retainingcomponents to their non-retaining positions; and moving at least one ofthe first and second pumping cartridge retaining components to itsretaining position.

[0012] In certain such embodiments, the selected position is chosen sothat the first portion of the cartridge and the second portion of thecartridge are separated by a distance enabling both the first and secondpumping cartridge retaining components to be positioned in theirretaining positions. The selected position can then be obtained by thesteps of: moving the piston relative to the cylinder so that a distanceseparating the first portion of the pumping cartridge and the secondportion of the pumping cartridge comprising a portion of the pistonshaft is greater that an engaging distance separating the first portionof the pumping cartridge and the second portion of the pumping cartridgecomprising a portion of the piston shaft; and inserting the pumpingcartridge into the pump drive system so that during insertion of thecartridge into the pump drive system the piston is moved into theselected position, wherein the distance separating the first portion ofthe pumping cartridge and the second portion of the pumping cartridgecomprises the engaging distance.

[0013] In certain embodiments of the first series of embodiments, theselected position is indicated by a detectable position indicator, whilein these or other embodiments, after the moving step, a step of usingthe pumping cartridge in a medical pumping procedure is performed. Incertain of these or other embodiments, the pumping cartridge isconstructed and arranged to enable it to withstand and generates apressure of at least about 5,000 p.s.i., without failure or leakage.

[0014] In certain embodiments of the first series of embodiments, theselected distance is obtained by engaging the first portion of thepumping cartridge with the first pumping cartridge retaining component;moving the driveshaft of the pump drive system to a first end of itsrange, wherein the driveshaft is in its distal-most position in which adistance between a distal end of the driveshaft and the cylinder is assmall as possible; and then engaging the second pumping cartridgeretaining component with the second portion of the pumping cartridgecomprising the portion of the piston shaft.

[0015] In another series of embodiments, a method for reversiblycoupling a pumping cartridge to a driveshaft of a reusable pump drivesystem is disclosed. The method comprises: providing the reusable pumpdrive system with a first pumping cartridge retaining componentconfigured and positioned to enable it to engage a first portion of thecartridge, the first pumping cartridge retaining component beingadjustable between a retaining position and a non-retaining position;providing a driveshaft of the reusable pump drive system with a secondpumping cartridge retaining component configured and positioned toenable it to engage a second portion of the cartridge comprising aportion of a piston shaft of the pumping cartridge, the second pumpingcartridge retaining component being adjustable between a retainingposition and a non-retaining position; inserting the pumping cartridgeinto the pump drive system; adjusting the first pumping cartridgeretaining component to the retaining position; moving the driveshaft ofthe pump drive system to a first end of its range, wherein thedriveshaft is in its distal-most position in which a distance between adistal end of the driveshaft and the cylinder is as small as possible;and engaging said second pumping cartridge retaining component with thesecond portion of the cartridge comprising a portion of the piston shaftof the pumping cartridge, so as to couple the piston shaft to thedriveshaft.

[0016] In yet another series of embodiments, a method for coupling apresterilized pumping cartridge to a reusable pump drive assembly isdisclosed. The method comprises: positioning a piston assembly portionof the pumping cartridge in a first position within the cylinder, thefirst position being proximal to an operating region of the cylinder inwhich a piston reciprocates during operation; sterilizing at least acylinder assembly portion of the pumping cartridge; inserting thecartridge sterilized in the sterilizing step into the pump driveassembly; engaging a first retaining component of the pump driveassembly with a first portion of the cartridge; and engaging a secondretaining component of a driveshaft of the pump drive assembly with thepiston assembly portion of the cartridge. In certain embodiments of themethod, before sterilizing the cartridge, a step of sealing the pumpingcartridge in sterilizable packaging can be performed. In certain ofthese or other embodiments, the cartridge may be removed from thesterilizable packaging after sterilization.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are schematic are not intended to bedrawn to scale. In the figures, each identical, or substantially similarcomponent that is illustrated in various figures is typicallyrepresented by a single numeral or notation. For purposes of clarity,not every component is labeled in every figure, nor is every componentof each embodiment of the invention shown where illustration is notnecessary to allow those of ordinary skill in the art to understand theinvention. In the drawings:

[0018]FIG. 1 is a schematic cross-sectional illustration of portions ofa pumping cartridge assembly according to one embodiment of theinvention;

[0019]FIG. 2 is a schematic cross-sectional illustration of portions ofa cartridge inserted into an adaptor on a drive shaft that connects to apump drive (not illustrated), according to one embodiment of theinvention;

[0020]FIG. 2A is a schematic illustration of one embodiment of a pistonshaft engaging member of the pump drive shaft of FIG. 2;

[0021]FIG. 3 is a schematic cross-sectional illustration of portions ofa pumping cartridge assembly and an adaptor on a drive shaft thatconnects to a pump drive (not illustrated) illustrating certaindimensional and positional relationships among the components, accordingto certain embodiments of the invention; and

[0022]FIG. 4 is a schematic cross-sectional illustration of portions ofa pumping cartridge assembly and an adaptor on a drive shaft thatconnects to a pump drive (not illustrated) illustrating certaindimensional and positional relationships among the components, accordingto certain embodiments of the invention.

DETAILED DESCRIPTION

[0023] To more clearly illustrate certain aspects of the invention, aparticular, exemplary embodiment is described below. Numerous variationsare possible that encompass the same invention, and the invention islimited only by the claims appended hereto, and is not limited to theexemplary configurations and dimensions set forth in this detaileddescription.

[0024]FIG. 1 is a schematic illustration showing a pumping cartridgeassembly, according to an embodiment of the invention, generally labeled1. The cartridge, in this embodiment, has two parts, a piston assembly10 and a cylinder assembly 30. The piston assembly 10 has a connectingregion 12 and a body region 28. The connecting region 12 comprises aterminal knob 14, a groove 16, and a shaft 18 meeting body 20 at lip 19.Body region 28 has a body 20, a fluid inlet 21 connecting with a checkvalve 24 (the structure of which is described in greater detail in US2002/0176788-A1); and a piston 22 carried on body 20 and having asealing flange 26 (the structure of which is described in greater detailin US 2002/0176788-A1). The flange 26, in certain embodiments, protrudesslightly beyond the diameter of the body 20 and the piston 22 to providea seal against the cylinder wall. The flange 26 may be designed to beerodible in use. The check valve 24 may be oriented so that fluid canmove into inlet 21 and out of the check valve, but cannot flow back intothe check valve when the piston compresses the fluid. In other words,the check calve 24 may be arranged so that fluid flows to the right(“distally”) in the cartridge as illustrated.

[0025] The other portion of the cartridge of the particular embodimentillustrated is the cylinder assembly 30. The cylinder assembly 30comprises a wall 32 surrounding a cavity 34. The cavity may be slightlybroader at a proximal portion 36 forming a piston storage region toaccommodate the flange 26 when the piston is not in use. This “parked”position can prevent or reduce irreversible deformation of the flange 26during storage, and is also useful for positioning of the piston, asdescribed below. A second check valve is positioned at 38, likewiseoriented so that fluid flows only to the right (distally). An outletfitting 40 carries a barb or other hose connection 42, and a positioningnotch 44. In normal operation, the piston reciprocates in a defined zone46, which is distal of the “parking” zone (i.e. piston storage region)demarcated by relief 36.

[0026] Many other detailed constructions of a cartridge are possible;several are illustrated and/or described in US 2002-0176788-A1. As willbe seen below, some features of a cartridge that may be advantageous foruse in certain embodiments of the invention are the existence ofpositioning elements on each of the piston assembly and the cylinderthat comprise or are functionally equivalent or similar to groove 16 andnotch 44. A second feature, provided in some embodiments, is the abilityof the piston assembly to remain assembled in the cartridge whileoutside of (proximal to) its normal operating zone, i.e., to be parkedor stored.

[0027]FIG. 2 is a schematic illustration of a cartridge inserted into anadaptor 60 on a drive shaft that connects to a pump drive mechanism (notillustrated). The drive mechanism will typically will comprise a motorwith appropriate controls, gearing, etc., and will be configured tocause the drive shaft adaptor 60 to reciprocate in the proximal/distaldirection. Drive shaft adaptor 60 has a cavity 62, which may be slightlylarger in diameter than piston shaft 18, and a back end at 68 and afront end at 70. Drive shaft adaptor 60 also may have one or more pistonshaft retaining components, such as one or more movable pins (orfunctional equivalent) 64. Pins 64 may have a rounded inner end 66designed to facilitate engagement with and to fit into groove 16 on thepiston shaft 18. When pin 64 is lowered and groove 16 is below pin 64 sothat the lower end 66 of the pin is in the groove, then the pistonassembly 10 is locked to drive shaft adaptor 60 and can reciprocate withit.

[0028] When pin 64 is raised, piston shaft 18 can be withdrawn fromcavity 62 and removed from the adaptor 60. Apparatus for raising andlowering pins 64 or equivalent is not illustrated, and may take manyforms, as would be apparent to those skilled in the art. In oneembodiment, FIG. 2A, a pair of pins 64 connected to a ring 65, which canbe looped around an elongated raising member (not shown), and slidefreely along the raising member when the drive shaft reciprocates. Whenthe driving mechanism is turned off and the raising member is raised,the pins are lifted sufficiently to allow removal or inserting of apiston shaft 18. With such a design, removal is possible at any point inthe stroke of the driveshaft. The pins could be replaced with a blade,or prongs, or other devices, and moved to engage the shaft, and removedto disengage the shaft, from any direction, including from below, orfrom the side, or from more than one direction, as would be apparent tothose skilled in the art. Insertion of the pair of pins 64 can be bygravity, but in some embodiments there is a bottom segment to the loopso that the raising member can also push the pins downward so as toengage groove 16 (see FIG. 2A.)

[0029] Referring again to FIG. 2, a block 80 has a cylindrical passage82 through it that may be slightly larger in diameter than cylinderouter wall 32. Associated with block 80 is a pump cartridge cylinderretaining component 84 with an inner end 86 that is sized andpositionable to fit into notch 44 of the cylinder assembly. Retainer 84is shown in a closed configuration in which it retains the cylinderassembly 30 in the passage 82, and retainer 84 may be configured so thatit can be raised to release the cartridge, or to allow insertion of thecartridge. The raising mechanism can take any of a variety of forms, aswould be apparent to those skilled in the art, and is not illustrated.Optionally, the raising mechanism for retainer 84 may be coupled to theraising mechanism for pin 64, in embodiments which allow thesimultaneous operation of the two latching mechanisms.

[0030] Driveshaft adaptor 60 operates within a drive assembly (notillustrated) in which the position of block 80 is fixed. (Othercomponents of the drive assembly can typically include the housing andthe motor and its controls, which are typically fixed in relation toblock 80). The pump drive assembly (which may also be called a console,or similar terms) is typically covered with a housing preventingoperator contact with moving parts and electrical or electroniccomponents, etc. Pin 64 may be connected to a lifting and loweringmechanism, which in one embodiment, as described above, is constructedso that pin 64 can reciprocate along with driveshaft adaptor 60, andstill be raised when removal of the removable pumping cartridge from thepump drive assembly is desired. Optionally, the pump drive assembly maybe constructed, for example by provision of mechanical or electronicinterlocks, so that neither pin 64 nor retainer 84 can be raised whiledriveshaft 60 is in motion.

[0031] The exemplary configuration illustrated in FIG. 2 demonstratesone of the problems that could occur when inserting a cartridge into thedrive assembly, and embodies one inventive solution, as described below.If driveshaft adaptor 60 is in its most proximal (to the left asillustrated) position, and/or piston assembly 10 is in its most distalposition, then pin 64 may not be able to become engaged with groove 16,even when the cartridge is fully inserted so that notch 44 can beengaged by retainer 84, unless the components are configured, accordingto the invention, such that certain relative dimensions of the cartridgeand driveshaft adaptor are provided, according to the invention, asdescribed below.

[0032]FIG. 3 presents one set of controlled dimensions according tocertain embodiments of the invention. The front and back ends of thecartridge are shown, as well as proximal 61 and distal 63 positions ofthe driveshaft adaptor 60, the groove 16 and the piston 22. Distance (a)is the distance separating proximal engaging pin 64 and distal engagingpin 84 on the reusable pump drive assembly, when driveshaft adaptor isin its most distal position at the end of a discharge stroke. Distance(b) is the distance separating proximal engaging pin 64 and distalengaging pin 84 on the reusable pump drive assembly, when driveshaftadaptor is in its most proximal position at the start of a dischargstroke. Distances (a) and (b) should be selected so that they correspondto the distances between groove 16 and groove 44 of the pumpingcartridge, when the piston is in the fully distal position and fullyproximal positions, respectively, in the normal operating zone ofcylinder 32. The distance (c), representing the difference between (a)and (b) should thus be about the same as the travel distance of thepiston and of the driveshaft during a pump stroke. Accordingly, it maybe advantageous for cartridges and drive assemblies to be constructed toa common standard of dimensions (a) and (b) so as to be more effectivelyusable together.

[0033] Referring now to FIG. 4, the distance (d) between pin 64 and thefront edge 70 of the driveshaft adaptor 60 may be essentially the sameas the distance between the groove 16 and the lip 19 of the pistonassembly 10. Alternatively, the distance between the groove 16 and thelip 19 of the piston assembly 10 could be somewhat longer than distance(d), or the lip 19 may not be present at all, in some embodiments. Inthese or other embodiments, the distance (e) between the pin 64 and theback of the driveshaft cavity 68 may be essentially the same as thedistance between the groove 16 and the proximal end of the knob 14 (orfunctional equivalent).

[0034] Taking into account the above-discussed dimensionalrelationships, it is possible to arrange the reusable drive assembly andpumping cartridge configurations to facilitate reliable insertion of apumping cartridge into a drive assembly so that the piston groove isproperly positioned to be engaged by pin 64, or functional equivalent,once the cartridge is inserted into the block 80 or equivalent andpositioned so that retainer 84 or equivalent can be engaged. In a firstmethod of assembly, the piston assembly 10 is initially positionedproximally of the operating zone 46, i.e., “parked” proximally of theoperating region (see FIG. 1). In the design shown in FIG. 1, this isthe proximal end 48 of cavity 34. This region can optionally be machinedto have a flange relief zone 36, in which the flange 26 on piston 22 isnot compressed. Then, the piston can be positioned in this zone duringmanufacture, sterilization, and/or shipping, so that the sterilizedcartridge is delivered to a customer ready to be inserted into the driveassembly without further manipulation. When the piston is pre-positionedin this way, the act of pushing the pumping cartridge into the driveassembly until it stops tends to facilitate the correct positioning ofthe lip 19 or of the knob 18 to allow for the engagement of thedriveshaft adaptor 60 and engagement of pin 64 into groove 16, therebyreversibly connecting the piston assembly with the driveshaft.

[0035] In an alternative embodiment, the initial position of the pistoncan be irrelevant if certain control features are added to the driveassembly. In this embodiment, the cartridge is first inserted into block80 and, optionally, retainer 84 is engaged. Then the driveshaft adaptor60 is moved to its extreme distal position, under manual or electroniccontrol. With proper dimensioning, as discussed above, this can ensurethat groove 16 is positioned so that it can be engaged by pin 64,thereby connecting the piston assembly to the driveshaft adaptor. As anoption, proper connection could be detected, for example by sensing thedepth to which pin 64 penetrates into chamber 62 when engagement isattempted. Such an embodiment could also be supplemented by adding acontrolling element that would position the driveshaft adaptor 60 at itsmost forward (distal) position upon shutdown of the drive assembly, orat its startup. This embodiment is also compatible with a pre-parkedpiston assembly version of the pumping cartridge, discussed above.

[0036] Useful additional features can be provided in certainembodiments. One optional feature is the provision of means forselectively controlling which of a variety of pumping cartridge typescan be used with a particular drive assembly. For example, a cartridgeof a first type requiring a higher pressure than other types ofcartridges might be configured to not fit into or otherwise be unusablein an older drive assembly that cannot drive a cartridge to the requiredpressure. In one embodiment, the selective control means could compriseprojections attached to outlet element 30 (see FIG. 1), or to otherelements remaining outside of the drive assembly, that would preventfull insertion of the cartridge into the block 80 unless the driveand/or block had a mating feature, into which the pins could slide. Inanother embodiment, the cartridge and the drive assembly could containelectronic elements so that one could read the other's configuration,and would send signals to the operator, or to a system controller in theconsole, indicating a mismatch, and optionally interrupting the startingprocess of the drive assembly.

[0037] In the exemplary embodiment described above, the engagingmechanism between the reusable pump drive assembly and the pumpingcartridge piston has been described as a pair of pins 64. The pins slideinto the groove 16 on opposite sides of the piston shaft, as if the pinswere a miniature tuning fork. In certain embodiments, the dimensions (e)and (d) (see FIG. 4) are selected such that the high force applied tothe piston shaft in the compression stroke can be absorbed by lip 19and/or knob 14 so that the pins 64 are not subject to high shearingforces. In such embodiments, the pins may only need to be configuredwith sufficient strength to enable them to withstand and transmit to thepiston shaft, the lower force needed to slide the piston proximally onthe return stroke. However, any of a variety of other latchingmechanisms could provide the same or equivalent effect. As noted above,mechanical equivalents comprise any means of placing an engaging memberso that it intrudes into groove 16, so that the piston is pulledbackward during the return stroke.

[0038] The engaging/latching mechanism for engaging the piston shaftdoes not need to be locatable/movable inside of cavity 62, but couldalso, or alternatively, be mounted on forward face 70 of driveshaftadaptor 60 to engage a groove or other feature of the piston shaft. Forexample, in an embodiment where a groove is provided just proximally oflip 19, the piston shaft could be engaged there by a suitably positionedengaging mechanism.

[0039] Another embodiment for achieving operable engagement between thepiston shaft and cavity 62 of the drive adaptor 60 involves providing aconfiguration allowing the closing of (i.e reduction in diameter of)driveshaft cavity 62 upon piston shaft 18. For example, the driveshaftadaptor 60 could have a longitudinal cut through its cross-sectionextending distally through forward face 70 and could be squeezed shut bya collet, clamp, etc. Or, in another embodiment, a collet element couldbe rotated to induce grasping of piston shaft 18. In anotheralternative, the groove 16 in piston shaft 18 could be replaced by aslot or a hole in or through piston shaft 18. This alternative couldrequire providing a means for controlling the rotational orientation ofpiston shaft 18 within cavity 60.

[0040] Removable/disposable pumping cartridge configurations that can beused, or can be modified, for example as described below, to be usable,in the context of the present invention are described in US2002-0176788-A1, along with information regarding materials ofconstruction of the various components and methods of fabrication. Manysuch cartridges are suitable for use in the pressure range of 20,000p.s.i or more. For designs for use at such high operating pressures,operating with relatively short piston stroke lengths and at highreciprocation frequency can be advantageous. The following recitescertain exemplary ranges of dimensions that may be advantageouslyemployed in practicing certain embodiments of the invention in whichpumping cartridges are intended to be operated at pressures in the5,000-20,000+ p.s.i. pressure range. In such embodiments, piston shaft20 may have a diameter of between about 7 to 13 mm. The stroke length(distance (c) in FIG. 3) may be in the range of between about 3 to 12mm., depending both on the desired volume delivery rate and on drivespeed. The shortest distance from notch 44 to groove 16, i.e., distance(a) in FIG. 3, may be in the range of between about 6 to 9 cm. When a“parking region” for the piston is present in the pumping cartridgecylinder, its length may be similar to the stroke length, but somewhatlarger than the length of the piston 22, for example in the range ofbetween about 5 to 15 mm.

[0041] As disclosed in US 2002-0176788-A1, in certain embodiments, atleast some of the conventional roles of pistons and cylinders can bereversed, so that, for example, a piston can be held stationary while acylinder assembly is moved back and forth. Likewise, a sealing element,analogous to flange 23 of piston 22 (see FIG. 3) may be positioned on apiston (as illustrated in FIG. 3), and/or on the wall of a cylinder.Such variations are considered to be included within the scope of theinvention.

[0042] While several embodiments of the invention have been describedand illustrated herein, those of ordinary skill in the art will readilyenvision a variety of other means and structures for performing thefunctions and/or obtaining the results or advantages described herein,and each of such variations, modifications and improvements is deemed tobe within the scope of the present invention. More generally, thoseskilled in the art would readily appreciate that all parameters,dimensions, materials, and configurations described herein are meant tobe exemplary and that actual parameters, dimensions, materials, andconfigurations will depend upon specific applications for which theteachings of the present invention are used. Those skilled in the artwill recognize, or be able to ascertain using no more than routineexperimentation, many equivalents to the specific embodiments of theinvention described herein. It is, therefore, to be understood that theforegoing embodiments are presented by way of example only and that,within the scope of the appended claims and equivalents thereto, theinvention may be practiced otherwise than as specifically described. Thepresent invention is directed to each individual feature, system,material and/or method described herein. In addition, any combination oftwo or more such features, systems, materials and/or methods, providedthat such features, systems, materials and/or methods are not mutuallyinconsistent, is included within the scope of the present invention. Inthe claims (as well as in the specification above), all transitionalphrases or phrases of inclusion, such as “comprising,” “including,”“carrying,” “having,” “containing,” “composed of,” “made of,” “formedof,” “involving,” and the like shall be interpreted to be open-ended,i.e. to mean “including but not limited to” and, therefore, encompassingthe items listed thereafter and equivalents thereof as well asadditional items. Only the transitional phrases or phrases of inclusion“consisting of” and “consisting essentially of” are to be interpreted asclosed or semi-closed phrases, respectively. In cases where the presentspecification and a document incorporated by reference includeconflicting disclosure, the present specification shall control.

What is claimed:
 1. A method for reversibly coupling a pumping cartridgeto a reusable pump drive system, the method comprising: providing thereusable pump drive system with a first pumping cartridge retainingcomponent configured and positioned to enable it to engage a firstportion of the cartridge, the first pumping cartridge retainingcomponent being adjustable between a retaining position and anon-retaining position; providing a driveshaft of the reusable pumpdrive system with a second pumping cartridge retaining componentconfigured and positioned to enable it to engage a second portion of thecartridge comprising a portion of a piston shaft of the pumpingcartridge, the second pumping cartridge retaining component beingadjustable between a retaining position and a non-retaining position;preparing the pumping cartridge for connection to the reusable pumpdrive system by placing a piston of the pumping cartridge in a selectedposition relative to a cylinder of the pumping cartridge; inserting thepumping cartridge into the reusable pump drive system; adjusting thefirst and second pumping cartridge retaining components to theirnon-retaining positions; and moving at least one of the first and secondpumping cartridge retaining components to its retaining position.
 2. Themethod of claim 1, wherein the selected position is chosen so that thefirst portion of the cartridge and the second portion of the cartridgeare separated by a distance enabling both the first and second pumpingcartridge retaining components to be positioned in their retainingpositions.
 3. The method of claim 2 wherein the selected position isobtained by the steps of: moving the piston relative to the cylinder sothat a distance separating the first portion of the pumping cartridgeand the second portion of the pumping cartridge comprising a portion ofthe piston shaft is greater that an engaging distance separating thefirst portion of the pumping cartridge and the second portion of thepumping cartridge comprising a portion of the piston shaft; andinserting the pumping cartridge into the pump drive system so thatduring insertion of the cartridge into the pump drive system the pistonis moved into the selected position, wherein the distance separating thefirst portion of the pumping cartridge and the second portion of thepumping cartridge comprises the engaging distance.
 4. The method ofclaim 1, wherein the selected position is indicated by a detectableposition indicator.
 5. The method of claim 1, further comprising afterthe moving step, the step of: using the pumping cartridge in a medicalpumping procedure.
 6. The method of claim 1, wherein the selecteddistance is obtained by engaging the first portion of the pumpingcartridge with the first pumping cartridge retaining component; movingthe driveshaft of the pump drive system to a first end of its range,wherein the driveshaft is in its distal-most position in which adistance between a distal end of the driveshaft and the cylinder is assmall as possible; and then engaging the second pumping cartridgeretaining component with the second portion of the pumping cartridgecomprising the portion of the piston shaft.
 7. The method of claim 1,wherein the pumping cartridge is constructed and arranged to enable itto withstand and generates a pressure of at least about 5,000 p.s.i.,without failure or leakage.
 8. A method for reversibly coupling apumping cartridge to a driveshaft of a reusable pump drive system, themethod comprising: providing the reusable pump drive system with a firstpumping cartridge retaining component configured and positioned toenable it to engage a first portion of the cartridge, the first pumpingcartridge retaining component being adjustable between a retainingposition and a non-retaining position; providing a driveshaft of thereusable pump drive system with a second pumping cartridge retainingcomponent configured and positioned to enable it to engage a secondportion of the cartridge comprising a portion of a piston shaft of thepumping cartridge, the second pumping cartridge retaining componentbeing adjustable between a retaining position and a non-retainingposition; inserting the pumping cartridge into the pump drive system;adjusting the first pumping cartridge retaining component to theretaining position; moving the driveshaft of the pump drive system to afirst end of its range, wherein the driveshaft is in its distal-mostposition in which a distance between a distal end of the driveshaft andthe cylinder is as small as possible; and engaging said second pumpingcartridge retaining component with the second portion of the cartridgecomprising a portion of the piston shaft of the pumping cartridge, so asto couple the piston shaft to the driveshaft.
 9. A method for coupling apresterilized pumping cartridge to a reusable pump drive assembly, themethod comprising: positioning a piston assembly portion of the pumpingcartridge in a first position within the cylinder, the first positionbeing proximal to an operating region of the cylinder in which a pistonreciprocates during operation; sterilizing at least a cylinder assemblyportion of the pumping cartridge; inserting the cartridge sterilized inthe sterilizing step into the pump drive assembly; engaging a firstretaining component of the pump drive assembly with a first portion ofthe cartridge; and engaging a second retaining component of a driveshaftof the pump drive assembly with the piston assembly portion of thecartridge.
 10. The method of claim 9, further comprising before thesterilizing step, a step of sealing the pumping cartridge insterilizable packaging.
 11. The method of claim 10, further comprisingafter the sterilizing step, a step of removing the cartridge from thesterilizable packaging.